Enhancing capacity evaluation of Canadian bridges with structural monitoring data

The Canadian Highway Bridge Design Code uses the concept of a target reliability index for evaluating the load-carrying capacity of existing bridges. This index, which is based on risk to human life, is related to three aspects of uncertainties inherent in a bridge: element behaviour, system behaviour and inspection level. It is assumed that all bridge inspections are manual. Citing examples of tests on many instrumented bridges, the paper proposes another level of inspection, which is done with the help of electronic instruments and tests under controlled vehicle loads. The paper proposes simple additions to the clauses of the Code, which can be used to determine the optimum load-carrying capacities of existing bridges where structural monitoring information is available.